Problem: Solve for $x$ : $3x + 5 = 5x + 9$
Solution: Subtract $3x$ from both sides: $(3x + 5) - 3x = (5x + 9) - 3x$ $5 = 2x + 9$ Subtract $9$ from both sides: $5 - 9 = (2x + 9) - 9$ $-4 = 2x$ Divide both sides by $2$ $\dfrac{-4}{2} = \dfrac{2x}{2}$ Simplify. $-2 = x$